Letter (copy of extract) to an unnamed recipient; London
MLA
Petty, William, Sir, 1623-1687. Letter (copy of extract) to an unnamed recipient; London. Folder 16811. 1648 September 8. https://collections.library.yale.edu/catalog/10034179.
APA, 6th edition
Petty, William, Sir, 1623-1687. (["Folder 16811"])(1648 September 8)[Letter (copy of extract) to an unnamed recipient; London]. https://collections.library.yale.edu/catalog/10034179.